A user interface (UI) refers to a mechanism by which a user and a computer can interact with one another. The purpose of a so-called natural user interface (NUI) is to allow a user to interact with a device in a “natural” manner, free from artificial constraints imposed by certain input devices such as mice, keyboards, remote controls, and the like. Examples of NUI methods include those utilizing “free-space” motion gesture detection using cameras (such as stereoscopic or time-of-flight camera systems, infrared camera systems, Red, Green, Blue (RGB) camera systems etc.), accelerometers/gyroscopes or other motion sensors, radar or radar-like sensors etc; voice and speech recognition; intention and goal understanding; touch sensitive displays, particularly when combined with gesture recognition whereby the user can make (single or multi-touch gestures) on the touchscreen; gaze tracking etc.